Kovacs Zoltan <kovacsz@pc10.radnoti-szeged.sulinet.hu> writes:
> There seems to be an optimizer problem in 7.1beta3. The query you can see
> below worked fast in 7.0.2 but in 7.1beta3 is rather slow. The problem is
> that an 'index scan' has been changed to a 'seq scan'. Details:
This is fixed in current sources: I get
Subquery Scan sd_user_grant (cost=5.16..5.22 rows=1 width=61) -> Aggregate (cost=5.16..5.22 rows=1 width=61)
-> Group (cost=5.16..5.18 rows=3 width=61) -> Sort (cost=5.16..5.16 rows=3 width=61)
-> Nested Loop (cost=0.00..5.14 rows=3 width=61) -> Seq Scan on pg_shadow (cost=0.00..1.01
rows=1width=32) -> Index Scan using sd_grant_pkey on sd_grant (cost=0.00..4.07 rows=3
width=29)
regards, tom lane